| Message ID | 20210920112405.1299667-5-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/4] block: factor out a blk_try_enter_queue helper | expand |
On 9/20/21 04:24, Christoph Hellwig wrote: > Don't switch back to percpu mode to avoid the double RCU grace period > when tearing down SCSI devices. After removing the disk only passthrough > commands can be send anyway. ^^^^ sent? > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 108a352051be5..bc026372de439 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -188,9 +188,11 @@ void blk_mq_freeze_queue(struct request_queue *q) > } > EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); > > -void blk_mq_unfreeze_queue(struct request_queue *q) > +void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) > { > mutex_lock(&q->mq_freeze_lock); > + if (force_atomic) > + q->q_usage_counter.data->force_atomic = true; > q->mq_freeze_depth--; > WARN_ON_ONCE(q->mq_freeze_depth < 0); > if (!q->mq_freeze_depth) { > @@ -199,6 +201,11 @@ void blk_mq_unfreeze_queue(struct request_queue *q) > } > mutex_unlock(&q->mq_freeze_lock); > } > + > +void blk_mq_unfreeze_queue(struct request_queue *q) > +{ > + __blk_mq_unfreeze_queue(q, false); > +} > EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); > > /* > diff --git a/block/blk.h b/block/blk.h > index e2ed2257709ae..6c3c00a8fe19d 100644 > --- a/block/blk.h > +++ b/block/blk.h > @@ -51,6 +51,7 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, > void blk_free_flush_queue(struct blk_flush_queue *q); > > void blk_freeze_queue(struct request_queue *q); > +void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic); > void blk_queue_start_drain(struct request_queue *q); > > #define BIO_INLINE_VECS 4 > diff --git a/block/genhd.c b/block/genhd.c > index b3c33495d7208..fe23085ddddd6 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -596,6 +596,7 @@ void del_gendisk(struct gendisk *disk) > /* > * Allow using passthrough request again after the queue is torn down. > */ > + blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); > blk_mq_unfreeze_queue(q); > > if (!(disk->flags & GENHD_FL_HIDDEN)) { I don't see any code that passes 'true' as second argument to __blk_mq_unfreeze_queue()? Did I perhaps overlook something? Thanks, Bart.
On Mon, Sep 20, 2021 at 08:29:49PM -0700, Bart Van Assche wrote: >> blk_mq_unfreeze_queue(q); >> if (!(disk->flags & GENHD_FL_HIDDEN)) { > > I don't see any code that passes 'true' as second argument to > __blk_mq_unfreeze_queue()? Did I perhaps overlook something? No, I did not finish actually implementing the suggestion from Ming properly, sorry.
diff --git a/block/blk-mq.c b/block/blk-mq.c index 108a352051be5..bc026372de439 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -188,9 +188,11 @@ void blk_mq_freeze_queue(struct request_queue *q) } EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); -void blk_mq_unfreeze_queue(struct request_queue *q) +void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic) { mutex_lock(&q->mq_freeze_lock); + if (force_atomic) + q->q_usage_counter.data->force_atomic = true; q->mq_freeze_depth--; WARN_ON_ONCE(q->mq_freeze_depth < 0); if (!q->mq_freeze_depth) { @@ -199,6 +201,11 @@ void blk_mq_unfreeze_queue(struct request_queue *q) } mutex_unlock(&q->mq_freeze_lock); } + +void blk_mq_unfreeze_queue(struct request_queue *q) +{ + __blk_mq_unfreeze_queue(q, false); +} EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); /* diff --git a/block/blk.h b/block/blk.h index e2ed2257709ae..6c3c00a8fe19d 100644 --- a/block/blk.h +++ b/block/blk.h @@ -51,6 +51,7 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, void blk_free_flush_queue(struct blk_flush_queue *q); void blk_freeze_queue(struct request_queue *q); +void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic); void blk_queue_start_drain(struct request_queue *q); #define BIO_INLINE_VECS 4 diff --git a/block/genhd.c b/block/genhd.c index b3c33495d7208..fe23085ddddd6 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -596,6 +596,7 @@ void del_gendisk(struct gendisk *disk) /* * Allow using passthrough request again after the queue is torn down. */ + blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q); blk_mq_unfreeze_queue(q); if (!(disk->flags & GENHD_FL_HIDDEN)) {
Don't switch back to percpu mode to avoid the double RCU grace period when tearing down SCSI devices. After removing the disk only passthrough commands can be send anyway. Suggested-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/blk-mq.c | 9 ++++++++- block/blk.h | 1 + block/genhd.c | 1 + 3 files changed, 10 insertions(+), 1 deletion(-)